1) Technical Field
The present invention relates to a hoisting winch assembly comprising at least two preferably axially parallel drums spaced from each other axially, which can be driven in synchronism with each other by two motors via a transmission assembly. The invention furthermore relates to a crane, in particular a gantry and/or container crane, with such hoisting winch assembly.
2) Description of the Related Art
The document DE 10 2009 050 584 A1 shows a container crane whose hoisting gear includes two axially parallel drums spaced from each other axially, i.e. in the direction of the longitudinal drum axis, which can be driven by a drive unit arranged centrally between the drums. This drive unit comprises a torque motor in the form of a multi-pole, permanently excited synchronous motor which drives the drums by means of cardan shafts, wherein in the drums transmissions are arranged, which are driven by the cardan shafts and reduce the motor speed. Such drive of the hoisting winches by a common motor ensures the synchronous run of the two drums, but only is used primarily for limited performance ranges, as a common motor otherwise cannot provide the performances required for both hoisting winches or would be dimensioned so large that the specified mounting dimensions and the specified axial spacing of the drums, which only provides a limited gap between the opposite end faces of the drums, might no longer be maintained. The position of the two cable drums to a large extent is defined by the fact that the usually four outgoing cables must be guided through existing openings in the steel construction with a predetermined deflection angle.
Although with a common drive motor, which drives both drums, an exact synchronous run of the drums can be achieved, it has therefore been proposed already to use two separate motors for driving the drums and to arrange the same beside the hoisting winches in order to be able to maintain the limited distance measure between the drums. The two cable drums here can be coupled with each other by a spur-gear transmission which can be arranged between the drums and can transmit the complete power of both motors for both drums. As the spur-gear transmission protrudes from the coaxial drums transversely to the same, the motors can be arranged beside the drums in a manner axially parallel to the drums. Due to the coupling of the drums by said spur-gear transmission it also is ensured that the drums rotate absolutely synchronously. In case of emergency, the system also can operate with only one of the two motors.
The motors arranged beside the drums however in turn lead to arrangement problems or constraints during installation, as the motors are to be arranged in a particular sector, so as not to collide with the cables running off. On the other hand, the assembly of the hoisting winch system is very expensive. The two drums, the spur-gear transmission, the two electric motors and the usually provided brakes each must be aligned individually and be fixed on the supporting structure. For this purpose, the bearing surfaces regularly spaced apart from each other several meters must exactly be machined mechanically in order to avoid alignment errors between the drum axes or alignment errors from the spur-gear transmission axes to the drum axes and the motor axes.
Proceeding therefrom, it is the object underlying the present invention to create an improved hoisting winch assembly and an improved crane with such hoisting winch assembly, which avoid disadvantages of the prior art and develop the latter in an advantageous way. In particular a compact, lightweight hoisting winch assembly is to be created, which is easy to mount and also can provide high performances with a favorable efficiency.